Simple WooCommerce plugin for eBooks download

I have a WooCommerce store that sells both printed books and eBooks in digital format (pdf and epub). I need a simple and straightforward plugin, similar to the free EditionGuard DRM one (you can find it in the Wordpress plugin repository), and I don't mind if you build it on that one, that does the following: All eBooks are downloadable through a partner gateway, that is, they are not locally stored as files on our server. Instead, when a user orders an eBook through our Woocommerce store (and the order has the status 'Completed'), the download link that is created is composed from an external base link URL, let's say https;//[login to view URL] and a couple of variables added to it: ?distribuitorID=[id_distribuitor_ACS]&sharedSecret=[shared_secret_ACS]&ordersource=[ordersource_ACS]&format=[format_produs]&isbn=[isbn_produs]&orderID=[id_tranzactie_acs] These variables are: product ISBN (already defined in the standard WooCommerce product meta, and it's unique for the format, meaning there's a ISBN for the pdf and a different one for the epub), product format (pdf or epub, already defined in the variable product), order ID and two other parameters: distribuitorID and sharedSecret, which are fixed and are like a user/password unique to our relationship with the partner/supplier, the same for all downloads. Preferably these two should be as editable fields somewhere in the admin panel in Wordpress, but could also be hardcoded in the plugin if it's too much of a hassle. Lastly, ordersource is also a static 4-letter code that is the same for all orders. It's like an identifier for us towards the supplier. All eBooks are Variable Product, with 2 variations: PDF and EPUB. Each of these variants are virtual & downloadable products. So: I need a plugin that integrates with Woocommerce, adds an optional checkbox to virtual products (and only to them), like 'This is a partner eBook', and those products, when ordered, will be downloadable through the generated link as described above. If the 'This is a partner eBook' checkbox is not checked, those products will fallback to the default WooCommerce behaviour / system in regards to the way they are downloaded. We don't have any of those at the moment, but would leave the possibility open for the near future, as we plan on having downloadable free eBooks which we will store locally on the server and they won't go through the partner gateway. I will supply all needed documentation to the winning bidder, if requested, and answer all questions. Thanks!